<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>css-notes</title>
  <style>
    div {
      width: 100px;
      height: 100px;
      background: red;
      position: relative;
      animation-name: myfirst;
      animation-duration: 5s;
      animation-timing-function: linear;
      animation-delay: 2s;
      animation-iteration-count: infinite;
      animation-direction: alternate;
      animation-play-state: running;
      /* Firefox: */
      -moz-animation-name: myfirst;
      -moz-animation-duration: 5s;
      -moz-animation-timing-function: linear;
      -moz-animation-delay: 2s;
      -moz-animation-iteration-count: infinite;
      -moz-animation-direction: alternate;
      -moz-animation-play-state: running;
      /* Safari and Chrome: */
      -webkit-animation-name: myfirst;
      -webkit-animation-duration: 5s;
      -webkit-animation-timing-function: linear;
      -webkit-animation-delay: 2s;
      -webkit-animation-iteration-count: infinite;
      -webkit-animation-direction: alternate;
      -webkit-animation-play-state: running;
      /* Opera: */
      -o-animation-name: myfirst;
      -o-animation-duration: 5s;
      -o-animation-timing-function: linear;
      -o-animation-delay: 2s;
      -o-animation-iteration-count: infinite;
      -o-animation-direction: alternate;
      -o-animation-play-state: running;
    }

    @keyframes myfirst {
      0% {
        background: red;
        left: 0px;
        top: 0px;
      }
      25% {
        background: yellow;
        left: 200px;
        top: 0px;
      }
      50% {
        background: blue;
        left: 200px;
        top: 200px;
      }
      75% {
        background: green;
        left: 0px;
        top: 200px;
      }
      100% {
        background: red;
        left: 0px;
        top: 0px;
      }
    }

    @-moz-keyframes myfirst /* Firefox */
    {
      0% {
        background: red;
        left: 0px;
        top: 0px;
      }
      25% {
        background: yellow;
        left: 200px;
        top: 0px;
      }
      50% {
        background: blue;
        left: 200px;
        top: 200px;
      }
      75% {
        background: green;
        left: 0px;
        top: 200px;
      }
      100% {
        background: red;
        left: 0px;
        top: 0px;
      }
    }

    @-webkit-keyframes myfirst /* Safari and Chrome */
    {
      0% {
        background: red;
        left: 0px;
        top: 0px;
      }
      25% {
        background: yellow;
        left: 200px;
        top: 0px;
      }
      50% {
        background: blue;
        left: 200px;
        top: 200px;
      }
      75% {
        background: green;
        left: 0px;
        top: 200px;
      }
      100% {
        background: red;
        left: 0px;
        top: 0px;
      }
    }

    @-o-keyframes myfirst /* Opera */
    {
      0% {
        background: red;
        left: 0px;
        top: 0px;
      }
      25% {
        background: yellow;
        left: 200px;
        top: 0px;
      }
      50% {
        background: blue;
        left: 200px;
        top: 200px;
      }
      75% {
        background: green;
        left: 0px;
        top: 200px;
      }
      100% {
        background: red;
        left: 0px;
        top: 0px;
      }
    }
  </style>
</head>
<body>
<p><b>注释：</b>本例在 Internet Explorer 中无效。</p>
<div></div>
</body>
</html>
